I played in several PDGA sanctioned Leagues last year and accepted cash several times. I never thought about it effecting my status to play the AM majors. Does it??? I was still invited to Worlds this year so my guess is that it does not. In the "prize" column on my PDGA stats page it does not list any winnings for Pro.

From the League FAQ:TDs can run their leagues pretty much however they run them now using best average scores, a points system, best 4 of 10 finish positions or handicaps to determine nightly and final league standings. Payouts will not be reported to the PDGA so amateurs may even get cash payouts if the TD prefers and they will not lose their amateur standing.